Radioreception



July 6 1926. 1,591,660

H. CORY RADIORECEI-TION Filed Oct. 25', 1 924 Eel/Fey 60m.

I 12:1 c Paitcnicc clunky I M n-049cm GE? GHIECAGQ, 11114335501ELAIJIQRFIGEPTIGN. v

scni invcntiou lino to do with im in radio 1'. :cniion. in has to docspccicliy iviiii imgn-o'i emenis in the IQq'jfifr iiion of vcry iiigiifrcqucncy radio Waves such as arc used for ti'ci'isinission oi signaland More fcziiwurcs of the pros cni; invc opiiccoic :fiiic rcccption Li. counii and Will pol iiiculm'ly d.

tcrcii m 'cz-vicc. Tiifiofi operating con-- diiions e o. "W Govcricizicn in tlic frco ucnc iigtli. of she radio fro quoncy on 7 so H,Wide variation. in 'iilii') load. on the radio fi ec ncncy ircnsiiorincroccasioned, by

vai-icioic ioading oi tiic vacuum. ibuiccs.

When "using: gnrcvicns foi ins of Radio frequency ti'cnsiormczg fincrois gcncrally produccd an annoying Screech oi' howl when the tuningcondensci's sn'c adjusted to can tnin capaoicy miucs; ci." a diifei'cntbut equally annoying noicc in the loud speaker whcn on iiianic scuriicn't in the vacuum iubc uccd frci' ncncy a'mplificaiion incrcoscdabove a ccla't'ain definite value.

Various theories have. been advanced as to iJliQ iih'iGiS reason forchose objectionable effects, but 'w izhoijic izlic'nccd of consideringino some in dc i, it may oc stated here that by using no mo :ncqucncytrains-"formers coo-- bodying inc fcciorcs of the present invention Ihave oco-n able to iargciy and often fully cyciccn'ic ilic c'forcsziidobjectionable col-cots in many whom they previously oxis'icifi, and overof Wzwo length and radio frequency und load for inexcess of incmmzncrcici. demands of the circuit.

1'. lm-vc discovered. that the above mon- Lioncd oio'jsctionniilc cficcts, as Well as others, may no ovcircomc o2" eiiminatcd by provid ing;tho i'cdic liroqncncy iamnsfcmicr itself with on odditionci third coilof proper oils-mics: 223cc catcher 533, 19%.

o large number of 50 "no toned, and iii sizc and properly rclcicd to thoprimary and sccondory coils and properly arranged, the presence of whichthird coil has boon actuaL ly and rcpcatcdly demonstrated in practice tofully overcome the above n'lcntioned cl)- jcctionolile features andprovide a. greatly impi'ovcd opcration'in oil conditions.

Radio frequency transformers provided with this improved feature may beused in different arrangements of circuit and hook ups and in systems ofsimple arrangement as WGil as those which are more compiicatcd andelaborate.

In cctuai practice I have discovered that by building ihc radiofrequency transformer with both its primary and secondary coils Wound intho some dircction, and then by "placing a i-l'lll'fl Winding injuxtaposition to tho aforesaid windings, said third winding beingpreferably Wound in the opposite dix'cciion compared to the prinmry andsecondary, and. tho terminals of said third win-dingbeing left opencircuitcd, very remarkable improvement in operation of the receivingcircuii. is produced provided the coils of the transformers are properlyrelnted to each other. In izhis connection, I have obtaincd verysatisfactory results if t'hc secondary coil. is composed of asinglelieiix of closely Wound who placed on the outside of a thin shell,such as a bakelite tube, and the primary consists of a smaller number ofturns ofwire closely Wound into a single helix and placed Within one endof the tube on which the secondary is placed, both primary secondarybeing wound in the some direction, d e third coii preferably consistingof 9, single helix of Wire hav ing its turns; closely Wound in theoppositc direction, the number of turns of the third coiii beingintermediate in number between cw. of the rimary and secondary, and thethird coil being placed immcdiately outside of e socondory coil. andoithe opposite end tlicieof from'thc position of the primary.

In a given. instance sevcntyfive turns 0! N01 2 2 double cotton coveredcopper wire W .cc Wound on tho (mi/side of a Bakelite tuEc 2% inchesoutside diameter and 2 4 inches inside diameter and 3 inches long. Tiiiswinding constiutcd doc secondary of the iui-unsi'ormcr. Eleven turns ofNo. 24 double cotton covered copper wire were wound on a mandril of suchdiameter that the finished coil wonid jus'i enter the bake-

